Planning to do a long trip with my Kona Sutra
I build it with a flatbar instead of dropbar (I prefer)
I want 180mm disc (I prefer)
I also want to use my old SLX Postmout brake (I prefer)
I found this trick : FM –> PM + PM160 –> PM180
Well I agree that it is awful but if it works safely for me and the bike, I will go for it. Do you have any info on that?
Thanks !
by CertainBicycle315
7 Comments
I mean it should hold….
That being said I’d check the bolts pretty often. This setup will most definitely cause a lot of leverage when braking and that can cause loosening or even cracking of bolts or the adapters.
I don’t know how heavy your full setup (bike, you, equipment etc) is. This will also cause a lot of load on this setup. Just keep an eye on the bolts and any bending in the adapter.
Also check if your pads are making full contact with the disc. I once used an adapter and had about a millimeter of the pad non contacting the disc, this caused excessive wear and lessened braking performance.
Sometimes physics take precedence over your preferences. Personally, I would not trust this.
I’d use a longer screw and double lock nuts if it’s possible
Is that a Kona sutra? I have that same frame in my basement just waiting to be built
Generally speaking, no.
I would not recommend this and would never run this configuration on my own bike.
If you absolutely must have 180mm get a peak torque 180mm flat mount adapter and a flat mount caliper. Or consider running a 160mm rotor with your current adapter but using a post mount 4 piston caliper.
I would remove the small adapter and go to 160mm with just one adapter (assuming that’s a 180mm) unless you bikepack with super long descends i guess? Or at least see if there is one adapter to cover the whole thing.
It’s probably fine if you torqued everything but kinda sketchy lol
My bet would be that the first time you stick a heavy bag on that rack, you bump it and it starts making noise. Seems like the left/right movement would go wrong pretty quickly.